Shielded tubing or bellows



June 22, 1948. n. w."FENTREss SHIELDED TUBING 0R BELLO-WS Filed lay 3, 1944 INVENTOR.

Patented June 22, 1948 PATENT DFFICE SHILDED TUBING on. BELLoWs David Wendell Fentress, Barrington, Ill., assignor to Chicago Metal Hose Corporation, Maywood, Ill., a. corporation of Illinois l Application May 3, 1944, Serial No. 533,984

1s claims. l

This invention relates to flexible tubing and bellows structures, and particularly to means for protecting the walls and convolutions thereof from contact with and the deleterious action of fluids conducted therethrough.

Itis an object of the invention to provide a flexible tubing or bellows structure of improved construction and operating characteristics. More specifically stated it is an object of the invention to provide an improved flexible tubing or bellows of the convoluted type, wherein the tubing convolutions are protected from the deleterious actions of conducted fluids, and wherein the tubing imparts a minimum resistance to flow of the conducted fluids, whereby to minimize line loss or pressure drop therein.

A further object of the invention is to provide a flexible tubing or bellows structure of the fore-l going type, which can be readily fabricated and constructed.

A still further object of the invention is to provide a flexible convoluted tubing or bellows structure, with an interposed lining structure, wherein the lining may act as a bend limiting means for the tubing, if desired, and wherein the tube walls and lining may be given different operating characteristics whereby, for example, the walls may be constructed to facilitate exibility whereas the lining is constructedto impart maximum, durability and wear characteristics to the structure.

Another object of the invention is to provide an improved exhaust -unit for internal combustion engines.

Still another object of the invention is to provide a supenposed plate type tubing or bellows structure with an interposed lining construction, of improved construction.

Various other objects, advantages and features of the invention will be apparent from the following specication when taken in connection with the accompanying drawings, wherein certain preferred embodiments are set forth for purposes of illustration.

In the drawings, wherein like reference numer- 45 (ci. 13s-50) 5 invention; and

Figs. 5 and 6 are detail illustrative views, similar to Fig. 4, but showing further modified structural embodiments.

In the drawings the invention has been illustrated as applied lto the exhaust line of an internal combustion engine, as the invention, in certain of its principal aspects is particularly adapted for a use of this character. It is to be understood, however, that the principles of the invention are adapted for use with flexible tubings and bellows generally, for various uses and applications wherein such structures may be employed.

Referring more specifically to the drawings, and first to the embodiment illustrated in Figs. 1, 2 and 3, in Fig. 1 an aircraft structure is diagrammatically and partially shown, as indicated by the reference numeral I 0. The aircraft includes a driving internal combustion engine I I, which-may be of conventional form, having an exhaust manifold I2. The exhaust conduit leading from the exhaust manifold comprises a first rigid section or pipe I3, rigidly secured to the exhaust manifold, and a second rigid section or pipe I4, rigidly aiixed to the body of the aircraft, by means of a support bracket I5. -In install-ations of this character, the engine ll is conventionally mounted upon the aircraft vehicle body by means of a flexible mounting, and during operation shifts slightly relative to the body as the driving torque is applied. The rigid pipe section I3, being rigidly carried by the engine, accordingly partakes of slight shifting movements in respect to the body supported .pipe section I4, during operation of the structure. To accommodate these shifting movements between the rigid pipe sections I 3 and Il, a flexible tubing unit, generally indicated by the numeral I6, is interposed between the rigid pipe sections.

The details of the tubing unit are best illustrated in Figs. 2 and 3. As shown, the tubing unit comprises a circular flange member I8, by means of which the unit may be secured to the rigid pipe I3, and a circular flange I9, by means of which the unit may be secured at its opposite end to the rigid pipe I4. Interposed between the y flanges I8 and I9 are a series of circular profiled metal plates, secured together to form a flexible tubing or bellows structure. Specically there is provided a group of plates 20, generally s-shaped in cross section, interposed between and secured to a group of plates 2|, of the cross sectional shape shown. The outer flanges 22 of the plates overlle and are secured to flanges 23 of the plates 2|, by means of a circular seam resistance weld. as indicated at 24. Similarly the inner flanges 25 of the plates 2U are secured to an intermedlate complementaryshaped portion 26 of the plates 2| by means of a circular seam-resistance weld, as indicated at 21.

A particular feature of the structure is the manner in which means-is arranged internally of the convoluted plates for protecting the plate convolutlons from direct or ir`pinging contact with the tubing conducted fluids, which are the hot exhaust gases from the internal combustion engine in the particular embodiment illustrated. As shown in Fig. 2, the baille or lining means for the tubing is formed as a direct extension of the plates 2|. To this end, as will be seen, the plates 2| are provided with extensions 30 underlying and protecting the flexible tubing convolutlons. These extensions are adapted to lie in juxtaposition, as shown, and form a substantially smooth central bore through the tubing for the conducted fluids. At the same time the extensions 30 are spaced slightly from each other, so that they do not interfere with the flexing movements of the plate walls as the tubing unit is flexed or shifted in service.

It will thus be seen that a structure is produced providing a substantially smooth bore for the conducted fluids, minimizing line loss and impedance to fluid flow through the unit. Additionally, the relatively fragile convoluted Walls of the unit are protected from direct impinging contact with the conducted fluids. While small spaces may be provided, as indicated at 3|, between the ends of the extensions 30 and the stepped portions 32 thereof, these spaces are so disposed that vfluids flowing through the unit, in the direction indicated by the arrow 33, are prevented from direct impinging contact against the convolution Walls. In this way the hot exhaust gases, in the embodiment of Fig. 1, are prevented from impinging contact against the convoluted walls of the unit, materially increasing the life and durability of the structure.

'I'he bailling of the convolution walls is obtained without impairing the desired flexibility of the structure. More particularly, the extensions 30 being in spaced relation, in no way interfere with the normal flexing movement of the convolution walls. At the same time, the extensions 30 being spa-ced only a slight distance apart, will automatically act to prevent flexing movements of the tubing beyond a predetermined degree. In other words, the baille extensions in no way interfere with the normal flexing movements of the unit, but operate automatically to prevent undue bending or movement.

The plates may be welded together by means such, for example, as illustrated in my copending application, Serial No. 505,805, filed October 11, 1943. In Fig. 2 a pair of cooperative welding rollers for forming the outer circular seam resistance weld 24 are dlagrammatically indicated at and 36. Cooperative welding rollers for forming the inner circular seam resistance weld 21 are dlagrammatlcally indicated at 31 and 38. As will be understood, the welding operations may be conducted progressively from the left to the right of the structure, as shown in Fig. 2, so that the baille extensions 30 do not interfere with the welding operations. Preferably the end plate dicated at 41.

2| is secured tothe flange I9 by means of a circular seam resistance weld 39, and the end plate 20 at the opposite end of the tubing is secured to the flange I8 by means of a. circular seam resistance weld 40, whereby to provide a complete welded unit with maximum durability and strength. The plates 20 and 2| are preferably of sheet metal, stamped into the desired profiled contour, as shown. The structure may thus be readily fabricated and constructed, providing a superposed convoluted plate type flexible tubing or bellows structure, with protective baille or lining means.

In Fig. 4 an embodiment is illustrated, generally similar to that shown in Fig. 2, but incorporating certain modified features of construction. In this instance the flexible convolutions are formed from a series of plates 45, suitably profiled to effect the functions of both the plates 20 and 2|, as illustrated ln Fig. 2. By this means the outer peripheral welding operation is eliminated.

Also in the structure of Fig. 4 the baille extens i'on 46, corresponding in function and purpose to the extension 30 previously described, is provided as a separate plate, welded to the convoluted plate by a circular seam resistance weld as ln- This Weld may be formed simultaneously with the weld 48 employed to secure the overlapped edges of adjacent plates together. The baille plates 46, being separate from the plates 45, may be constructed of special heat and wear resistant metal, and also, if desired, may have a. greater wall thickness than the flexible convoluted plates. By this means increased durability of the unit, when used for example as a hot gas exhaust unit, is secured. It is to be understood, however, that the plate 46 may be formed as an integral extension of the plate 45, as in the case of the extension 30, if desired.

Also as indicated in Fig. 4, th'e ends of the extension plates 46 may be in substantially abutting engagement with the intermediate extension plate portions 50, whereby to substantially close the opening between the baille extensions, corresponding to the opening 3| previously described. To permit the necessary flexing movements of the unit, the extension plates may be slotted as indicated at 5|. The arrangement shown lncreases the rigidity of th'e unit, while still permitting flexibility or movement as required.

In Fig. 5, a structural embodiment is illustrated, also generally similar to those previously described, except that in this instance the plate sets 55 and 56, forming the tubing or bellows unit, are butt welded at their juxtaposed edges by means of circular seam resistance welds as indicated at 51 and 58.

Also, as illustrated in Fig. 5, the baille extension corresponding to the extension 30 of Fig. 2 in this instance constitutes a plate portion 53 formed as an integral extension of the convolution plate 55,

and a plate 60 overlying the plate portion 59 is secured thereto by means of the circular seam resistance weld 6|. The lining plate 60 may be made of special heat resistant metal, the plates 59 and 6|) forming a composite structure of increased plate thlckness and of increased wear reslstant characteristics.

The welding operations, as illustrated in Fig. 5, may be carried out for example as set forth in my copendlng application, Serial No. 298,235, flied October 6, 1939, now Patent No. 2,347,185, dated April 25, 1944. Welding rollers for effecting the outer peripheral weld 51 are diagrammatically indicated at 62, and a welding table and cooperating welding roller for effecting the inner welds .S8-and 6I are diagrammatically indicated at 83 and 64. The inner welds 58 and 8l may be first formed, and the outer plate edges thereafter welded together.

As' will be understood; the various features heretofore set forth may be interchangeably employed. For example, in Fig. 6 a unit is illustratedcomposed of sets of convoluted plates 65 and 66, butt welded at their outer edges, as indicated at 61, and lap welded at their inner portions of engagement, as indicated at 68. As in the embodiment of Fig. 5, the baille extension is formed by means of a plate portion 10, constituting an integral extension of the plate 65, and a separate plate Il secured in position by means of a welded connection 12.

As will be understood, butt or overlapped joints maybe interchangeably used at the inner and outer points of engagement, to meet the requirements of any particular installation.

It is obvious that various changes may be made in the specific structural embodiments set forth without departing from the spirit of the invention. Accordingly the invention is not to be limited to the specific embodiments shown and described, but only as indicated in the following claims.

The invention is hereby claimed as follows:

1. A tubing or bellows structure comprising a cylindrical tube structure formed into an aligned series of annular convolutions, said convolutions being shiftable relative to each other to provide a flexible convoluted tubing structure, and baille means disposed internally of the convolutions, said baille means comprising a series of relatively shiftable plates secured to the annular convoluf,

tions, said plates forming bridging means between the convolutions to provide a relatively smooth internal bore within the tubing structure.

2. A tubing or bellows structure comprising a cylindrical tube structure formed into an aligned series of annular convolutions, the walls of said convolutions being flexible whereby said convolutions are shiftable relative to each other to provide a flexible convoluted tubing structure, and baiiie means disposed internally of the convolutions. said baiiie means comprising a series of relatively shiftable plates secured to the annular convolutions, said plates all projecting in the same direction within the tubing structure into juxtaposition to each other whereby to shield the tubing convolutions.

3. A tubing or bellows structure comprising a series of aligned profiled plates, said plates being iixedlysecured together along their engaged outer and'inner` portions to form a flexible convoluted structure, and baiile means disposed internally of the plates, said baille means bridging the plate convolutions and providing a relative smooth internal bore within the tubing structure.

4. A tubing or bellows structure comprising a series of aligned fprofiled plates, said plates being secured together along their engaged outer and inner portions to form a flexible convoluted tubing structure, and a series of baflies disposed internally of the plates, said bailies being secured to the plates and projecting in the same direction within the tubing int'o juxtaposition with each other whereby to shield the convoluted structure.

5. A tubing or bellows structure as deiined in claim 4, wherein said bailles are formed as integral extensions of the plates.

6. A tubing or bellows structure as defined in claim 4, wherein said bailies comprise separate plates circular seam welded to the tubing plates.

7. A tubing or bellows structure as defined in claim 4, wherein said bafiles comprise separate plates secured to the tubing plates, the baiiie plates having greater wear resistance characteristics than the tubing plates.

8. A tubing or bellows structure comprising a series of aligned proed plates, said plates being xedly secured together along their engaged outer and inner portions to form a flexible convoluted tubing structure, and a series of baiiles disposed internally of the plates, said bailles being secured to the plates and projecting in the same direction within the tubing into substantially abutting engagement with each other to effect the shielding of the convoluted structure, said baiiles being provided with slots extending axially of the tubing to permit the flexing of the tubing in operation.

9. A tubing or bellows structure comprising a cylindrical tube structure formed into an aligned series of annular convolutions, the walls of said convolutions being flexible whereby said convolutions are shlftable relatlveto each other to provide a flexible convoluted tubing structure, and baille means disposed internally of the convolutions, said bale means comprising a series of relatively shiftable plates secured to the annular convolutions, said plates being disposed in predetermined spaced relation from each other within the tubing, and being adapted to be brought into engagement when thetubing is iiexed a predetermined amount whereby the plates act as bend limiting means.

10. A tubing or bellows structure comprising a series of aligned proled plates, said plates be- Ling secured together along their engaged outer and inner portions to form a flexible convoluted structure, and bafiie means disposed internally of the plates, said baille means comprising a series of members secured to the plates and projecting into predetermined spaced relation from each other within the tubing. said members being adapted to be brought into engagement with l each other upon a predetermined flexing of the plates whereby to operate as a bend limiting means for the tubing structure.

l1. A tubing or bellows structure comprising a series of aligned proled plates, said plates oeing circular seam Welded along their engaged outer and inner portions to form a exible convoluted tubing structure, and a series of baffles disposed internally of the plates, said baiiies being secured to the plates and projecting in the same 'direction within the tubing into juxtaposition with each other whereby to shield the convoluted stnucture.

12. An exhaust conduit for transmitting exhaust gases and the like comprising a series of aligned profiled plates, said plates being circular seam welded together along their engaged outer and inner portions to form a exibleconvoluted tubing structure, and a series of baiiles disposed internally of the plates, said baiiles comprising a series of profiled members secured respectively to the plates and projecting in the direction of fluid flow within the tubing, said b'aiiies projecting into juxtaposition with each other forming a substantially continuous smoothbore within the tubing and shielding the convoluted tubing plates from direct rimpinging contact with the conducted fluids.

13. A tubing or bellows structure comprising a series of aligned proiiled plates, said plates be-v ing welded along their outer and inner. portions to form a flexible convoluted tubing structure, and a series of baes disposed internally of said plates, said baiiies comprising separate plates welded to said iirst plates and being arranged to project in the same direction within the tubing into juxtaposition with eachother whereby to shield the convoluted structure.

14. A tubing or bellows structure comprising a series of aligned proiiled plates, said plates being circular seam welded along their engaged outer and inner portions to fonrn a iiexible convoluted tubing structure, and a series of baies disposed internally of the plates, said bailies being formed as integral extensions of certain of said plates and arranged to project in the same direction within the tubing into juxtaposition with each other whereby to shield the convoluted structure. 16. A' tubing or bellows structure comprising ya cylindrical tubing struct/ure formed of an aligned series of individual annular convolutionsarranged shiftable relative to each other to provide a exible convoluted tubing structure, and baille means disposed internally of said convolutions, said baille means comprising a series of individual relatively shiftable plates secured to said annular convolutions, said plates forming bridge means vbetween said convolutlons to provide a relatively smooth internal bore within the tubing structure.

DAVID WENDELL FENTRESS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,145,434 Pechstein July 6, 1915 1,151,777 Fulton Aug. 31, 1915 1,255,577 Berry Feb. 5, 1918 1,560,789 Johnson et al Nov. 10, 1925 1,905,824 Bysthe Apr. 25, 1933 

